The objective of this investigation is to increase our understanding of the role of proteins in the regulation of neuronal function through a study of the intra-axonally transported proteins. Using the retinal ganglion cells of the rabbit visual system as an experimental model, these proteins will be characterized with regard to their physical properties, transport velocities, turnover rates, intracellular localization, identity and, if possible, function. Attention will be focussed upon proteins showing altered transport properties associated with neuronal stimulation, visual deprivation and development, with the hope that the characterization of these proteins will contribute to an understanding at the molecular level of such processes as regulation of transmitter synthesis, specification of interneuronal connections and synaptogenesis. Intra-axonal transport will be compared in different neuronal systems and in different species to establish on the one hand the degree of universality, and on the other hand the degree of uniqueness of the velocities and compositions of transported proteins. An aberrant transported protein which has been identified in the optic nerve and tract of albino animals will be analyzed further to determine its relation to the misrouting of retinal ganglion cell axons at the optic chiasm which is associated with the albino trait.